Lots of ways to go with this. If you shoot an AR in Service Rifle, you might want to consider one of the .22 conversion kits for the AR. The ones I've been exposed functioned pretty well, and there's no better practice for your regular rifle than using it for practice as well.
If you're just looking for something to practice with in .22, the Ruger 10/22 is a perennial favourite.
Bill
